The Genetics Core will establish a repository of DNA and genotypes on all participants of the University of Pittsburgh. The aims of the Genetics Core are: Aim 1) to collect and bank DNA from blood and brain tissues from all participants in the University of Pittsburgh ADRC. Aim 2), to generate genotype data for the APOE polymorphisms in the coding (codons 28, 112, 158) and regulatory (-491 A/T, -427 T/C, -219 6/T, -186 G/T and +113 G/C) regions, and other new genetic risk markers associated with late-onset Alzheimer's disease from DNA obtained in Aim 1, and Aim 3) to provide banked DNA (Aim 1) and genotype data (Aim 2) to the ADRC Data Registry Base and to ADRC affiliated R01 and pilot projects so that the DNA can be used for other genetic markers screening and genotype data can be used to assess the genetic risk for Alzheimer's disease.